Given that side a = 6
side b = 15
Use Pythagoras theorem to find out hypotenuse, h.
[tex] {h}^{2} = {a}^{2} + {b}^{2} \\ \\ {h}^{2} = {6}^{2} + {15}^{2} \\ \\ {h}^{2} = 36 + 225 = 261 \\ \\ h = \sqrt{261} [/tex]
[tex] \text{We know that } \sin(A) = \frac{b}{h} \\ \\thus \: \boxed{ \red{ \sin(A) = \frac{15}{ \sqrt{261} } }}[/tex]
